Aromatic diamines

ABSTRACT

NOVEL AROMATIC DIAMINES HAVING THE GENERAL FORMULA   ((2-NH2-PHENYL)-CO-X-)N-R   WHEREIN N IS AN INTEGER OF FROM 2 TO 8, X IS SULFOR OR OXYGEN, AND R IS AN N-VALENT HYDROCARBON RADICAL WHICH MAY BE INTERRUPTED BY O OR S ATOMS AND WHICH IS OBTAINED BY REMOVING OH OR SH GROUPS FROM A POLYOL OR POLYTHIOL HAVING A MOLECULAR WEIGHT OF LESS THAN 600, P ARE PREPARED BY REACTING A COMPOUND HAVING THE FORMULA (HX)NR WHERE X, N AND R ARE AS DEFINED ABOVE WITH ABOUT N-EQUIVALENTS OF AN ISATOIC ACID ANHYDRIDE IN THE PRESENCE OF A STRONG BASE. THE AROMATIC DIAMINES OF THE INVENTION ARE PARTICULARLY USEFUL AS THE ACTIVE HYDROGEN CONTAINING COMPONENT FOR REACTION WITH POLYISOCYANATES IN THE PREPARATION OF SYNTHETIC RESINS BY THE ISOCYANATE-POLYADDITION PROCESS.

United States Patent Office 3,817,940 Patented June 18, 1974 ABSTRACT OFTHE DISCLOSURE Novel aromatic diamines having the general formula NH: J

wherein n is an integer of from 2 to 8, X is sulfur or oxygen, and R isan n-valent hydrocarbon radical which may be interrupted by O or S atomsand which is obtained by removing OH or SH groups from a polyol orpolythiol having a molecular weight of less than 600, are prepared byreacting a compound having the formula (HX) R where X, n and R are asdefined above with about n-equivalents of an isatoic acid anhydride inthe presence of a strong base. The aromatic diamines of the inventionare particularly useful as the active hydrogen containing component forreaction with polyisocyanates in the preparation of synthetic resins bythe isocyanate-polyaddition process.

This is a division of application Ser. No. 171,381 filed Aug. 12, 1971.

The compounds according to the invention are new chain lengtheningagents for the synthesis of synthetic resins by the diisocyanatepolyaddition process. They have an advantageous influence both on theworking up process and on the mechanical properties of the syntheticresins obtained and therefore assume a pre-eminent position among thechain lengthening agents hitherto known.

Chain lengthening agents used for the synthesis of elastic polyurethaneresins, are, for example, aromatic diamines such as4,4'-diamino-3,3'-dichloro-diphenylmethane. These amines carry achlorine atom in the ortho position to the amino group. This chlorineatom reduces the reactivity of the aromatic amino group towards theisocyanate group, thereby providing advantageous conditions (e.g.suflicient pouring time) for working up in the liquid phase or for thefoaming process.

The present invention relates to aromatic diamines of the generalformula n represents an integer of from 2 to 8,

X represents oxygen or sulphur and R represents an n-valent saturated orunsaturated, straight chain or branched chain hydrocarbon radical, ifdesired, interrupted by oxygen and/or sulphur atoms, of the type whichmay be obtained by partial removal of the OH and/or SH groups from apolyol or polythiol of molecular weight 76 to 599.

in which The surprising observation was made that the ester group whichis in the ortho position to the amino group in the compounds accordingto the invention so greatly diminishes the reactivity of the amino grouptowards isocyanates that, as can be seen from kinetic measurements, thenew compounds take up an intermediate position, as regards theirreactivity, between aliphatic glycols which have hitherto been used aschain lengthening agents and the ortho-chloro-substituted aromaticdiamines already mentioned above. This means that the ester group in theortho position has a much stronger eifect in reducing the reactivity ofthe amino group than a chlorine atom in the ortho position.

The compounds according to the invention are therefore eminentlysuitable for the synthesis of polyurethane resins in enabling this to becarried out by an even more convenient process due to the substantialincrease in the pouring time combined with a shorter than averagesetting time which enables the cast synthetic resins to be quicklyremoved from the mould. This fact provides the necessary conditions forimproved technical working up.

Furthermore, the properties of the synthetic resins obtained areinfluenced very advantageously by the incorporation of the new chainlengthening agents.

The use of bifunctional products according to the in- .vention havingthe following constitution:

Z=alkylene radical having 2 to 18 carbon atoms, e.g.=

leads, for example, to soft synthetic resins'which have littleelasticity and are in some cases very suitable for the production offloor coverings, grouting compositions and pressure roller compositions.

The following are examples of compounds according to the invention:

0 0 ti 3 -O--(CH4)2O NH1 HzN preferred 0 O t it N Q HzN preferredpreferred NH: HzN

preferred NH: HrN

NH: O 8 CH3CH H-CHr-O- Hz-O-C preferred HzN CHg- O-[tCHD 201211preferred Sucrose radical N H:

which have a molecular weight of 76 to 599 and in which X, n and R havethe meanings already defined above are reacted with about n equivalents(about meaning 0.8 to 1.2 equivalents) of isatoic acid anhydride in thepresence of strong bases such as sodium hydroxide or triethylamine,preferably in solvents which do not react with isatoic acid anhydride,e.g. in ethers or ketones and preferably in tetrahydrofuran or dioxane,at temperatures generally in the region of 40 C. to 130 C. andpreferably in the region of 60 C. to 110 C. After filtration and removalof the solvent, the product of the process can be purified, e.g. byrecrystallisation from aqueous dioxane or ethanol.

If the compound R(XI-I), is to be reacted completely with isatoic acidanhydride, the quantity of isatoic acid anhydride used should be equalto n equivalents whereas if it is not intended to react all the XHgroups with isatoic anhydride, the quantity of isatoic acid anhydrideput into the reaction should be less than n equivalents. It is, however,preferable to react the compounds R(XH) completely with isatoic acidanhydride, using n or more than n equivalents of isatoic anhydride.

A typical example will now be given to explain the process ofpreparation:

134 g. (1 mol) of trimethylolpropane in 900 ml. of dioxane which hasbeen dried over 18 g. of potassium carbonate are heated to C. with 589g. (3.6 mol) of isatoic acid anhydride. After 81 l. of carbon dioxidehave escaped, the produce is filtered with suction. After removal of thesolvent on a rotary evaporator, the first product obtained is a syrupyliquid which soon crystallises.

450 g. of this crude product are recrystallised from 400 ml. of ethanolto yield 400 g. (82% of the theory) of white crystals of trimeth ylolpropane trianthranilate of melting point 106 C.

Calculated: C, 66.0%; H, 6.0%; N, 8.6%. Found: C, 66.0%; H, 6.3%; N,8.6%.

The following, for example, were obtained in analogous manner:

Butane diol dianthranilate; melting point: 107 C. to 108 C. Calculated:C, 65.8%; H, 6.15%; N, 8.54%. Found: C, 65.7%;H, 6.3%; N, 8.5%.

Thiodiglycol dianthranilate; melting point: 69 C. to 70 C. Calculated:C, 60.1%; H,5.5%; N, 7.8%; S, 8.9%. Found: C, 60.4%; H, 5.8%; N, 7.6%;S, 8.9%.

Diethylene glycol dianthranilate; melting point: C. to 106 C.Calculated: C, 62.8%; H, 5.85%; N, 8.5%. Found: C, 63.0%;H, 5.9%;N,8.2%.

Hexane diol dianthranilate; melting point: 74 C. to 75 C. Calculated: C,67.4%; H, 6.7%; N, 7.9%. Found: C, 67.5%; H, 6.9%; N, 8.0%.

A polyether of trimethylolpropane and ethylene oxide of averagemolecular Weight 306 which has been partly reacted (on 2 of the 3 OHgroups) with isatoic acid anhydride:

Polyether of trimethylolpropane and ethyleneoxide having an averagemolecular weight of 306 partly reacted (on 2 of the 3 OH groups) withisatoic acid anhydride: Viscous oil:

500 mg.l8.3 ml. N/lO HClO (theoretical).

Found: 18.15 ml. N/lO I-ICIO;

The present invention therefore relates to a process for the preparationof aromatic diamines having the general formula (theoretical).

NHz J in which n represents an integer of from 2 to 8:

X represents an oxygen or sulphur atom and R represents an n-valentsaturated or unsaturated, straightchain or branched chain hydrocarbonradical, if desired, interrupted by O and/or S atoms of the typeobtained by removal of OH and/or SH groups from a polyol or polythiolhaving a molecular weight of 76 to 599,

characterised in that a compound of the general formula (I-DO R having amolecular weight of 76 to 599 is reacted with more or less than nequivalents of isatoic acid anhydride in the presence of strong bases.

The strong base is preferably sodium hydroxide, 0.01 to 0.1 mol ofsodium hydroxide, preferably 0.05 mol of sodium hydroxide being used permol of HX groups.

The starting material of the general formula in which X, n and R havethe meaning already mentioned above may be polyols or polythioalcoholshaving a molecular weight of 76 to 599, e.g. propane-1,2-diol andpropane-1,3-diol, butanediol, hexanediol, nonanediol,trimethylolpropane, pentaerythritol, sorbitol, glucose,diethyleneglycol, thiodiglycol, hydroquinone,4,4-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyldimethylmethane orl,S-dihydroxynaphthalene. Diols having a molecular weight of 76 to 599and triols having a molecular weight of 92 to 599 are preferred. Otherstarting compounds which are also especially advantageous arepropanediol, butane-1,4-diol, hexane-1,6-diol, thiodiglycol, diethyleneglycol and trimethylolpropane.

The present invention also relates to the use of aromatic diamines ofthe general formula n represents and integer of from 2 to 8,

X represents an oxygen or sulphur atom and R represents an n-valentsaturated or unsaturated, straightchain or branched chain hydrocarbonradical if desired,

interrupted by O and/ or S atoms of the type which may be obtained bycomplete or partial removal of OH and/or SH groups from a polyol orpolythiol having a molecular weight below 600 as reactants forpolyisocyanates in the production of synthetic resins by the isocyanatepolyaddition process.

in which In this case, the aromatic diamines which may be used alsoinclude those which are obtained by reacting isatoic acid anhydride withpolyols or polythioalcohols which have a molecular weight below 76. Thismeans that apart from the polyols and polythiols already mentionedabove, compounds such as ethylene glycol or the correspondingthioanalogue are also suitable for use as starting materials for thecompounds which are to be used according to the invention.

The production of synthetic resins from the compounds according to theinvention is carried out by processes known per se, involving reactionswith polyisocyanates and higher molecular weight compounds which containend groups which are reactive with isocyanates. The process may becarried out by first reacting a calculated quantity of the highermolecular weight compounds, then adding the chain lengthening agentsaccording to the invention and then reacting the mixture either in thepresence or absence of a substance which decomposed to liberate a gas.

Another possibility consists in mixing the compounds according to theinvention with the higher molecular weight compounds and then carryingout the reaction with isocyanates. The reaction of the new chainlengthening agents with polyisocyanates may be carried out in thepresence of any of the additives known in polyisocyanate chemistry, e.g.catalysts, compounds which liberate gases or flame-retarding substances.

Higher molecular weight compounds which are especially suitable for thepresent process are higher molecular weight hydroxyl compounds, e.g. thefollowing: Conventional types of polyhydroxyl compounds having amolecular weight of 750 to 10,000, for example linear or slightlybranched polyesters with terminal hydroxyl groups which may be preparedby known processes, e.g. from monohydric or polyhydric alcohols andcarboxylic acids or hydroxycarboxylic acids, if desired, with theaddition of amino alcohols, diamines, hydroxylamines anddiaminealcohols. Especially to be mentioned among the polyesters are thealiphatic polycarbonates such as hexanediol polycarbonate andcaprolactone polyesters which are obtained by the polymerisation ofcaprolactone in the presence of starter molecules such as glycols.Linear or branched polyethers which may be obtained by thepolymerisation of alkylene oxides such as ethylene oxide, propyleneoxide, epichlorohydrin or tetrahydrofuran are also suitable. Copolymersof this type may also be used. Linear or branched addition productswhich may be obtained by the addition of the above mentioned alkyleneoxides, for example to polyfunctional alcohols, amino alcohols, oramines are also suitable.

The starting compounds for the process according to the invention arepreferably polyethers which contain at least 2 active hydrogen atoms andpreferably have a molecular weight of 750 to 10,000 in which at least10% of the hydroxyl groups present are primary OH groups. The primary OHgroups are determined by the method of Gordon Hanna and Sydney Siggia,Journal of Polymer Science, Vol. 5 6, pages 297-304 (1962). Polyethersof this type are prepared by reacting compounds which contain activehydrogen atoms, e.g. polyalcohols and polyphenols, with alkylene oxidessuch as ethylene oxide, propylene oxide, butylene oxide, styrene oxideor epichlorohydrin or with mixtures of these alkylene oxides, ifdesired, followed by tipping of the resulting polyethers with ethyleneoxide.

The following are examples of suitable polyalcohols and polyphenols:ethylene glycol, diethylene glycol, polyethylene glycol,propane-1,2-diol, propane-1,3-dio1, butane-1,4- diol, hexane-1,6-diol,decane-1,l0-diol, butyne-2-, diol-1,4, glycerol, butane-2,4-diol,hexane-1,3,6-triol, trimethylolpropane, resorcinol, di-tert.-butylpyrocatechol, 3-hydroxy- 2-naphthol, 6,7-dihydroxy-1-naphthol, 2,5dihydroxy-lnaphthol, 2,2-(p-hydroxyphenyl)propane, bis-(p-hydroxyphenyl)methane, tris-(hydroxyphenyl)alkanes such as1,1,2-tris-(hydroxyphenyl)methane or 1,1,3-tris-(hydroxyphenyl)propane.Other suitable polyethers include 1,2- alkylene oxide derivatives ofaliphatic or aromatic monoor polyamines such as ammonia, methylamine,ethylenediamine, N,N'-dimethylethylenediamine, tetraor hexamethylenediamine, diethylenetriamine, ethanolamine, diethanolamine,methyldiethanolamine, triethanolamine, aminoethylpiperazine, toluidine,o-, mand p-phenylenediamine, 2,4- and 2,6-diaminotoluene and2,6-diamino-pxylene and multinuclear and condensed aromatic polyaminessuch as 1,4-naphthylene diamine, benzidine, 2,2- dichloro 4,4diphenyldiamine and 4,4-diaminoazobenzene. Resinous materials of thephenol and resol type may also be used as starting materials.

All these polyethers have preferably been synthesized with ethyleneoxide as one of the starting materials and preferably contain at least10 percent of primary OH groups. The above mentioned polyethers may alsobe modified by reacting them with less than equivalent quantities ofpolyisocyanate.

Other higher molecular weight compounds which have active hydrogen atomsinclude the known polyacetals, polyester amides, polycarbonates andpolyols which contain urethane groups. The higher molecular weightcompounds with reactive hydrogen atoms to be used according to theinvention may also be used in mixtures with low molecular weightcompounds with active hydrogen atoms which have molecular weights of upto 750. Suitable low molecular weight compounds with active hydrogenatoms are especially the compounds which have hydroxyl groups, e.g.ethylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, glycerol,trimethylolpropane, castor oil or addition products, generally in themolecular weight region of 200 to 750, of alkylene oxides such asethylene oxide, propylene oxide or butylene oxide with low molecularweight compounds of this type which have active hydrogen atoms or withwater.

7 Higher molecular weight compounds which contain amino groups, e.g.those which have terminal amino groups, represented by the generalformula O-X R NH; J

in which n denotes an integer of from 2 to 8,

X represents an oxygen or sulphur atom and R represents an n-valentradical of the type which is obtained by removal of hydroxyl or mercaptogroups from an n-valent polyalkylene ether polyol or from a polyalkylenethioether polythiol, and which are prepared by a process characterisedin that compounds of the general formula (HX) R having a molecularweight of 600 to 10,000 are reacted with at least n equivalents ofisatoic acid anhydride in the presence of strong bases.

'In this case, the formation of urethane groups as chain linking groupsdoes not take place as in the polyurethane resins hitherto described butinstead, the synthetic resins produced contain urea groups in additionto ester and ether groups.

The isocyanates used may be any of the conventional polyisocyanates andpreferably the following: butane-1,4- diisocyanate,hexane-1,6-diisocyanate, octamethylene-1,8- diisocyanate; carboxylicacid ester diisocyanates, cycloaliphatic diisocyanates such as1-methyl-cyclohexane-2,4- and -2,6-diisocyanate and any mixtures ofthese isomers, cyclohexane-1,4- and -l,3-diisocyanate, dicyclohexyl-Inethane-4,4-diisocyanate, araliphatic diisocyanates such asxylylene-1,3- and -1,4-diisocyanate, aromatic diisocyanates such astolylene-2,4- and -2,6- diisocyanate and any mixtures of these isomers,phenylene-1,3- and -1,4-diisocyanate, diphenylmethane-4,4'-diisocyanateand naphthylene-l,S-diisocyanate. A certain amount of triisocyanatessuch as benzene-1,3,5-triisocyanate ortriphenylmethane-4,4,4"-triisocyanate may also be included. According tothe invention, the isocyanates preferably used are tolylene-2,4diisocyanate and tolylene-2,6-diisocyamate and isomeric mixturesthereof, diphenylmethane-4, 4-diisocyanate, naphthylene-1,5-diisocyanateand polyphenylpolymethylene polyisocyanates which may be obtained byaniline formaldehyde condensation followed by phosgenation and theirmixtures with tolylene-2,4- and/ or 2,6-diisocyanate, if desired, inadmixture with diphenylmethane-4,4-diisocyanate and its isomers.

According to the invention, the polyisocyanates used are Preferablysolutions of so-called modified polyisocyanates, i.e. solutions ofpolyisocyanates which have biuret groups in polyisocyanates which arefree from biuret groups and/or solutions of polyisocyanates which haveat least two NCO groups and at least one N,N'-disub stituted allophanicacid ester group in polyisocyanates which are free from allophanic acidester groups and/or solutions of reaction products of polyisocyanatesand divalents or higher valent compounds which contain hydroxyl groupsin polyisocyanates which are free from urethane groups and/or solutionsof polyisocyanates which contain more than one NCO group and at leastone isocyanuric acid ring in polyisocyanates which are free fromisocyanurate groups.

The solutions of modified polyisocyanates which are preferably used forthe invention generally contain 1 to 85% by weight and preferably to 50%by Weight of modified polyisocyanates.

The allophanate polyisocyanates may be prepared e.g. in accordance withBelgian Pat. 761,626. The polyisocyanates used for this purpose arepreferably diisocya- 8 nates such as tolylene-2,4-diisocyanate ormixtures of this with tolylene-2,6-diisocyauate.

Modified polyisocyanates used according to the invention may also besolutions of polyisocyanates which contain biuret groups inpolyisocyanates which are free from biuret groups. According to theinvention, it is preferred to use solutions at concentrations of 1 to85% by weight of polyisocyanates which contain biuret groups,represented by the following general formula:

in which R represents a C C alkyl radical, C to C cycloalkyl radical, Cto C aralkyl radical or C to C aryl radical and X represents hydrogen orthe group -c o-N -..M

R-NCO in which R has the meaning already given above and n represents aninteger of from 0 to 5 in polyisocyanates which are free from biuretgroups, the proportion of biuret polyisocyanates which have more than 3isocyanate groups being at least 20% by weight based on the totalquantity of biuret polyisocyanates. Polyisocyanates which contain biuretgroups may be prepared e.g. according to the method disclosed in BritishPatent Specification No. 889,050 or according to the method of GermanPatent Specification No. 1,101,394. The polyisocyanates preferably usedaccording to the invention are solutions in polyisocyanates which arefree from biuret groups of biuret polyisocyanates which have beenprepared by reacting either 2,4- and/or 2,6-tolylene diisocyanate,4,4'-dipheny1 methane diisocyanate and/or its isomers or apolyisocyanate mixture resulting from aniline formaldehyde condensationfollowed by phosgenation, with water or formic acid. The polyisocyanatesfor use according to the invention preferably contain 0.03 to 5% byweight and especially 0.1 to 2% by weight of chemically boundemulsifiers. These emulsifiers should contain OH, amino, amido, COO'H,SH or urethane groups and are therefore incorporated into thepolyisocyanate by reaction with the isocyanate groups.

The isocyanate components used as starting material may, moreover, bepolyisocyanates of the type which are characterised by containing acertain amount of urethane-containing polyisocyanates and, if desired,having a higher degree of branching than purely difunctionalisoeyanates. These isocyanates often contain 10 to and preferably 20 to50% of isocyanates which contain urethane groups dissolved inpolyisocyanates which are free from urethane groups.

The modified polyisocyanates may also be solutions of polyisocyanateswhich contain at least one isocyanuric acid ring in liquidpolyisocyanates which are free from isocyanurate groups. Polyisocyanateswhich contain such isocyanurate groups and processes for theirpreparation have been described, e.g. in German Patent SpecificationNos. 951,168; 1,027,394; 1,022,789 and 1,123,729 in British PatentSpecifications 821,158; 827,120; 856,372; 927,173; 920,080 and 952,931,in U.S. Patent Specification Nos. 3,154,522 and 2,801,244, in FrenchPatent Specification No. 1,510,342 and in Belgian Patent Specication No.718,994. Polyisocyanates having at least one isocyanuric acid ring arepreferably polymeric tolylene- 2,4- and/or -2,6-diisocyanates, ifdesired, mixed with 4,4'-diphenyln1ethane-diisocyanate or its isomers.These isocyanates which may be used according to the invention areobtained by dissolving the polyisocyanate which contains isocyanurategroups in the liquid polyisocyanates which are free from isocyanurategroups, generally in amounts of 1 to 85% by weight based on the weightof the resulting polyisocyanate solutions.

The polyisocyanates which are free from urethane groups or biuret groupsmay be any aliphatic, cycloaliphatic, aromatic or araliphaticisocyanates, e.g. those described in Liebigs Annalen der Chemie, Volume562 (1949), pages 755 et seq. Preferably, tolylene isocyanate or itsisomeric mixtures or isomeric mixtures of this type which have not beendistilled, diphenylmethane-4,4'-diisocyanate ordiphenylmethane-2,4-diisocyanate or the undistilled crude diisocyanates,naphthalene-1,4-diisocyanate, triphenylmethane-4,4,4"-triisocyanate,isophorone diisocyanate, polyphenylpolymethylene polyisocyanatesobtained by the condensation of aniline and/or alkyl substitutedanilines with formaldehyde followed by phosgenation or the isocyanateswhich contain adducts of carbodiimide and isocyanate, e.g. thoseobtained according to German Patent Specification No. 1,092,007, areused.

The production of self extinguishing polyurethane foam resins isgenerally carried out by the known one shot process. In this process,the foam resins are produced at room temperature and/ or elevatedtemperature simply by mixing the above described polyisocyanatesaccording to the invention with the higher molecular weight polyols,Water and/or other blowing agents and, if desired, emulsifiers and otheradditives as well as the auxiliary agents according to the inventionbeing used. Mechanical devices are advantageously used for this purpose,e.g. those described in French Patent Specification No. 747 143 and theprocess described in German Patent Specification No. 881,881.

Suitable emulsifiers are e.g. ethylene oxide or the addition products ofethylene oxide and propylene oxide with hydrophobic substances whichcontain hydroxyalkylene groups or amino groups or amido groups. Suitablecatalysts for the production of flame resistant, nonshrinking foamresins which contain urethane groups are tertiaryjriiiiines and/orsila-amines, N-substituted aziridines o r hexahydrotriazine, if desired,in combination with organic metal compounds. These catalysts vary in theextent to which they accelerate the diiferent partial reactions of foamformation. Whereas amines preferentially catalyse the expandingreaction, organic metal compounds have a preferential catalytic effecton the crosslinking reaction. The catalytic eflect on the expandingreaction, i.e. for example the reaction between isocyanate groups andwater with evolution of carbon dioxide, may vary according to theconstitution of the amines or silaamines. The quantity of catalystnecessary to achieve reaction times which are advantageous for thefoaming technique are determined empirically according to theconstitutions of the given catalyst. The amines used may be those wellknown for the production of polyurethane foam resins, for exampledimethyl benzylamine, N- methylmorpholine, triethylenediamine,dimethylpiperazine, 1,2-dimethylimidazole, dimethylethanolamine,diethanolamine, triethanolamine, diethylaminoethanol, N,N,N",N"-tetramethyl-1,3 butanediamine andN-methyl-N-dimethyl-aminoethylpiperazine.

The silaamines used are silicon compounds which contain carbon siliconcompounds, e.g. those described in German Patent Specification No.1,229,290. 2,2,4-trimethyl 2 silamorpholine and1,3-diethyl-aminomethyltetramethyldisiloxane may be mentioned asexamples, but bases which contain nitrogen, such as tetraalkylammoniumhydroxides and alkalies, alkali metal phenolates or alcoholates, e.g.sodium methylate, should also be noted. The organic metal compoundswhich may be used in combination with amines, silaamines andhexahydrotriazines according to Belgian Patent Specification No.

10 730,356 are preferably organic tin compounds, e.g. tin- (II)-octoateor dibutyl tin dilaurate.

Additives for regulating the cell structure may be used as may alsoorganic or inorganic fillers and dyes or plasticisers such as phthalicacid esters.

Foam resins produced by the process according to the invention areflameproof when produced with flame-retarding additives of known typeand are to be classified as self extinguishing in accordance with theASTM test D 169267 T. This most desirable property can be achieved bymeans of known flame retarding agents such as trichloroandtribromo-alkylphosphates. It is partly lost under extreme storageconditions such as high temperatures over prolonged periods of time.Permanent and substantial improvement in the already high flameresistance of the products of the process can 'be achieved e.g. bymodifying the modified polyisocyanate solutions with compounds whichcontain chlorine and/or bromine and which can be incorporated into thepolyisocyanates, i.e. which contain hydrogen atoms that are reactivewith isocyanates. As regards the elfect achieved, it is immaterial atwhat point these flame retarding agents which can be incorporated areintroduced, for example whether they are built directly into themodified polyisocyanate or added subsequently to the polyisocyanatesolutions or reaction mixtures.

The following are given as examples of flame-retarding agents which canbe incorporated: 2-chloroethanol, 2-bromoethanol, trichloroethanol,1,3-dichloropropanol, 1,2-dichloropropanol, 2-bromopropanediol, 1,1styrenechlorohydrin and styrene bromohydrin, bromoacetic acid.

The elastic and semielastic foam resins obtainable :by the processaccording to the invention may be used, for example, as cushioningmaterial, mattresses, packaging material, foils for backing, insulatingmaterial and, owing to their flame resistance, they can be used whereverthis property is particularly important, e.g. in motor vehicles, inaircraft construction and in transport in general. The foam resins maybe produced either by foaming in the mould or by manufacturing them frommaterial which has been foamed in blocks.

EXAMPLE 1 Chain lengthening agent used: Butanediol dianthranilate.Melting point 107-108 C. Calculated: C, 65.8; H, 6.15; N, 8.54. Found:C, 65.7; H, 6.3; N, 8.5.

parts of a prepolymer of tetrahydrofuran having an average molecularweight of 1700 and 2,6-diisocyanatotoluene having a free NCO content of4.1% and 15 parts of molten butanediol dianthranilate are cast at C. andthe resulting polyurethane resin is tempered at 110 C. for 24 hours.After this heat treatment, a soft synthetic resin which has thefollowing properties is obtained:

Tensile strength (DIN 53504) kg.wt./cm. 63

Elongation at break (DIN 53504) percent 890 Shore hardness A (DIN 53505)48 Elasticity (DIN 53512) percent 31 EXAMPLE 2 Chain lengthening agentused: T hiodiglycol dianthranilate. Melting point: 69-70 C. Calculated:C, 60.1; H, 55; N, 7.8; S, 8.9. Found: C, 60.4; H, 5.8; N, 7.6; S, 8.9.

200 g. of a polyester (OH number 56) obtained from adipic acid andethylene glycol are dehydrated in a vacuum at 130 C., and 40 g. of anisomeric mixture of 80% by weight of 2,4- and 20% by weight of2,6-tolylene diisocyanate are added at C.

The reaction mixture is then stirred for 30 minutes and evacuated toremove air for 30 seconds, and 36.6 g. of molten thiodiglycoldianthranilate are then run in with stirring. The mixture sets after 15minutes at 100 C. to form a soft polyurethane resin of low elasticitywhich has the following properties:

Tensile strength (DIN 53504) kg. wt./cm. 170

Elongation at break (DIN 53504) percent 740 Shore hardness A (DIN 53505)54 Elasticity (DIN 53512) percent; 16

EXAMPLE 3 Chain lengthening agent used: Butane-1,4-diol-dianthranilate.

200 g. of an aminopolyether which has been obtained by complete reactionof a polypropylene oxide of molecular Weight 2000 with 2 mols of isotoicacid anhydride are reacted with 40 g. of an isomeric mixture of 80% byweight of 2,4- and 20% by weight of 2,6-tolylene diisocyanates for /2hour at temperatures of 70 to 80 C. to form a prepolymer. The reactionmixture is then heated to 90 C. and at the same time it is evacuated andmixed at that temperature with molten chain lengthening agent withstirring. After 24 hours heating at 100 C., a synthetic resin which hasthe following properties is obtained:

Tensile strength (DIN 53504) kg. wt./cm. 154

Elongation at break (DIN 53504) percent 327 Shore hardness A (DIN 53505)87 Elasticity (DIN 53512) percent 29 EXAMPLE 4 Chain lengthening agent:Diethylene glycol dianthranilate. Melting point: 105-106" C. Calculated:C, 62.8; H, 5.85; N, 8.5. Found: C, 63.0; H, 5.9; N, 8.2.

The procedure is the same as in Example 3 but using 48.7 g. ofdiisocyanate and 59 g. of diethylene glycol dianthranilate. After 24hours heating at 100 C., a synthetic resin which has the followingproperties is obtained:

Tensile strength (DIN 53504) kg. wt./cn1. 168 Elongation at break (DIN53504) percent 485 Shore hardness A (DIN 53505) 85 Elasticity (DIN53512) percent 31 COMPARISON EXAMPLE Preparation of a hard polyurethanefoam resin Component A: 60 Parts by weight of (Z-ethyl) hexyl ester of4-chloro-3,S-diamino-benzoic acid, 40 parts by weight of an additionproduct of propylene oxide and trimethylolpropane (OH number 550), 1part by weight of silicone stabiliser, 3 parts by weight ofN-methyl-N'-(N,N- dimethylamino-ethyl)-piperazine and 10 parts by weightof monofiuoro trichloromethane are intimately mixed.

Component B: 730 Parts by weight of a polyether (dipropyleneglycol andpropylene oxide, OH number 148) are added dropwise to 660 parts byweight of 2,4-/2,6-tolylene diisocyanate (80:20) with stirring. Thetemperature rises to 50 C. The mixture is then heated to 80 C. and keptat this temperature until the NCO content is 17%.

11 Parts by weight of Component A and 230 parts by weight of Component Bare intimately stirred together and introduced into a closed metal mould(dimensions of mould (dimensions of mould 500 x 200 x 10 mm.). Thetemperature of the mould is 70 C. The reactive mixture starts to foamafter 25 seconds and gels after a further 35 seconds. After 10 minutes,the moulding is removed from the mould. The moulding has a solidmarginal zone and a cellular core.

Physical properties of the moulding: Elastic modulus in the bending test(DIN 53423) E =2400 kg. wt./cm.

Dimensional stability in the heat under bending stress according to DIN53424, bending stress approximately 3 kg. wt./cm. at a deflection of 10mm.:

HB =39 C.

EXAMPLE The chain lengthening agents used are an adduct of ethyleneoxide and trimethylolpropane having an average molecular weight of 306.Two OH groups of this adduct are reacted with isotoic acid anhydride toform anthranilic acid ester, the resulting molecular weight being 544.

The procedure is the same as in the comparison example except that 40parts by weight of the chain lengthening agent mentioned above are usedinstead of 40 parts by weight of the polyether (OH number 550) incomponent A, and parts by weight of component B are used instead of 230parts by weight of this component.

Physical properties of the moulded product:

Elastic modulus in the bending test (DIN 53423) kg. wt./cm.

Dimensional stability in the heat under bending stress according to DIN53423, bending stress approximately 3 kg. wt./cm. at a deflection of 10mm.:

HB =78 C.

EXAMPLE 6 Chain lengthening agent tripropylene glycol trianthranilate Amixture is prepared from 100.0 parts by weight of a polyether preparedby reacting propylene oxide and then ethylene oxide withtrimethylolpropane to result in approximately 60% of primary hydroxylgroups in the end positions and an OH number of 35.0, 2.5 parts byweight of water, 0.4 parts by weight of endoethylenepiperazine, 1.0parts by weight of triethylarnine and 6.0 parts by weight oftripropylene glycol dianthranilate, and the mixture is reacted with 36.0parts by weight of a mixture (NCO content 39.5%) of 60.0 parts by weightof 2,4-tolylene diisocyanate, 10.0 parts by weight of 2,6-tolylenediisocyanate and 30.0 parts by weight of a polymerised 2,4- tolylenediisocyanate (NCO content 20.8%

A foam resin which has the following mechanical properties is obtained:

What is claimed is:

1. Synthetic resins produced by the isocyanate polyaddition processcomprising reacting a polyisocyanate with an aromatic diamine of thegeneral formula wherein n represents an integer of from 2 to 8, Xrepresents an oxygen or sulphur atom, and R represents an nvalentsaturated or unsaturated, straight chain or branched chain hydrocarbonradical which may be interrupted by O or S atoms and is obtained by theremoval of OH or SH groups from a polyol or polythiol having a molecularweight below 600.

2. The resin of claim 1 wherein the aromatic diamine is 3. The resin ofclaim 1 wherein the aromatic diamine is c o O-(CHZ)G O o 0- 3,817,940 1314 4. The resin of claim 1 wherein the aromatic diamine is 7. The resinof claim 1 wherein the aromatic diamine is is C O O(CI-h) zS-(CHz)2-OC0- CH2 O mOIPH NH! HzN 5 I (I) cm-om- C-CHz-O-(CHzh-O-(LQ 5. The resinof claim 1 wherein the aromatic diamine is HzN C O O(CH:)z--O(CH2)2OC O(i H 0 NH, HzN 10 2 O Hm 0 Q 6. The resin of claim 1 wherein thearomatic diamine is HZN 0 T References Cited iQ 15 UNITED STATES PATENTS3,736,295 5/1973 Meckel et a1. 26077.5 AM N H2 E MAURICE J. WELSH,Primary Examiner CH3 CHT CH2 US. Cl. X-R. NH: 260-471 R

